B4J Question [SOLVED] Pocketbase SSE (using GET & POST)

[Mashiane]

Hi

I have been following the PocketBase API and all is well, however, I need a way to execute a method call that is not Put/Patch/Post/Delete.

Its SSE, as an example, all these work well with the current built in methods.

I need to call this

Thanks in advance.

Kind regards

Mashy

 

[tchart]

SSE is server side events. It’s like a one way web socket - hence the real-time name

see here

Server-Sent Events - is available on jServer ?

I'm reading a w3schools document where they talk about Server-Sent Events technology It is described as a system that allows you to send web pages from the server to the client So by reversing the normal data flow, it is no longer the client who has to query the server but it is the latter that...

www.b4x.com

 

[tchart]

Also worth reading this

W3Schools.com

W3Schools offers free online tutorials, references and exercises in all the major languages of the web. Covering popular subjects like HTML, CSS, JavaScript, Python, SQL, Java, and many, many more.

www.w3schools.com

 

[Mashiane]

I have come to understand what the issue is. In terms of these docs, one can have SSE working by first executing a GET & POST requests.

PocketBase - Open Source backend in 1 file

Open Source backend in 1 file with realtime database, authentication, file storage and admin dashboard

pocketbase.io

So I assumed that this was possible with HttpJob. I could be wrong, it does not seem possible.

How to reproduce.

1. Start pocketbase in debug mode to see what happens

pocketbase serve --debug

2. Execute a httpjob poststring to

http://127.0.0.1:8090/api/realtime.

This gives one a client id immediately on pocketbase, but the issue is getting this back on b4j.

Dim j As HttpJob
    j.Initialize("pb", Me)
    j.Download($"${baseUrl}/realtime"$)
    Wait For (j) JobDone(j As HttpJob)

By the time wait for fires, the session is closed and the client id cancelled.

 

[tchart]

So I assumed that this was possible with HttpJob. I could be wrong, it does not seem possible.

Thats my understanding as well - at least not out of the box.

If you look at the W3 example, the JavaScript initiates the "EventSource" and then waits for messages.

var source = new EventSource("demo_sse.php");
  source.onmessage = function(event) {
    document.getElementById("result").innerHTML += event.data + "<br>";
  };

There is a B4A library here that may help you but it depends what you are trying to do;

B4A Welcomes SSE

so, there's something called server side events (SSE). it apparently has something to do with notifications from a web server to a browser. i'm guessing it's what happens when you see an annoying pop-up message from a web server asking persmission to send you notifications. good luck with...

www.b4x.com

It appears to use this library;

GitHub - heremaps/oksse: An extension library for OkHttp to create a Server-Sent Event (SSE) client.

An extension library for OkHttp to create a Server-Sent Event (SSE) client. - heremaps/oksse

github.com

But I think this is for a B4A application receiving SSE from a web server.

 

[Mashiane]

I see and thanks @tchart .

I have been working on a b4x jPocketbase class that enables anyone to use Pocketbase within the b4x ecosystem.

The only thing outstanding is SSE.

Pocketbase CRUD REST API & SSE with PostMan and then HttpUtils

Hi CRUD Examples Attached PocketBase is an open source backend consisting of embedded database (SQLite) with realtime subscriptions, built-in users management, convenient dashboard UI and simple REST-ish API. It runs on Linux, Windows and Mac, You can get it here, https://pocketbase.io/ We...

www.b4x.com

The JavaScript calls for this from their documentation is not a train smash and as I am using the JS Dev Kit on that front, all is good.

I did check the B4a link for the SSE, looks very promising.

 

[Mashiane]

We might have some traction on this...

I was looking at Erels example and if I am correct, this is the same principle, https://www.b4x.com/android/forum/threads/consuming-http-streams.111542/#post-695615

As long as I can trap the data_arrived calls here this should work.